As an owner of a model 87(I know I can hear the sighs) and been thinking about the piston shortage.I came across this old topic after doing a search, I have read all the reply’s with interest. I work for an engineering company and work on the CNC mills most of the programmes are done on the computer CAD/CAM using a solid model.my question to you more knowledge people of these bikes.1- Is there any reason why a piston could not be machined from solid billet of Aluminium(I am not sure what grade but it would have to be a hard grade of Aluminium ) as opposed to forged pistons2- If the rings are also difficult to get for the T20 could the piston be made to use a more available ring say like from the Villiers engine of the same size.The above are just a thought and probably not possible

I see there is a secondhand plus 60 thou oversize 20T piston advertised on ebay at the moment as item 201146491430. From the photo it appears to be complete. Although there are still a few standard size 20T pistons to be found, the larger oversizes are in the hens teeth category. Sandy Ross (For info only, the ad referred to is nothing to do with me!)

Hi Laurence, I imagine it would be hard to find a +40 piston, I spotted this firm that makes pistons and piston rings, but to have an AMC piston made would cost an arm and a leg, but rings would be a possibility, essecially as a batch Mike

Hi Mike I have removed the barrel the +40 piston looks like it as not done a lot miles and the rings are look good and the barrel I will measure,I was hoping to find some new rings but it look like this will take a while or a not at all, so the link you have gave is worth a ring (no pun intended),to get a price. thank you.

I could be interested so long as the price us not very very high. Guess you would have to decide on what oversize to have made. No good having standard if everyong has had a rebore. Easier to bore the barrel to suit an oversizepiston . You would also need to be sure they have rings with them .

Hi. I have a set of 25T 40+ rings and a 20+ set that I no longer need. PM me if you need them and we can come to some arrangement. (probably some sort of swap as I live in New Zealand and don't use paypal.) On the 20t subject. Is there a reason that the Villiers 6e rings couldn't be used (both 59mm)? It may involve piston groove machining/shimming and a little (very careful) filing but I would be interested to know if it could be done. Just a thought.P.S I'm not greedy when it comes to the rings.(just enough to cover postage costs) Members here have been very helpful to me in the past.

Did anyone have any luck with the search for a manufacturer? Or has anyone found the holy grail of pistons (or rings). I have two engines sat in my kitchen now, 20T1373 just a set of casings with barrel (+.20") and a piston with nibbled lands and no rings, and also a complete engine V20TS9287 (less kickstart spring, a headbolts) needing rings and really a new piston again. Is it worth while trying to find a bike to go with the engines if the pistons are a problem?

Hi Colk2004 I have a model 87 with a T20 and have just found a piston on ebay they do come up but you have to wait,or you could try auto jumbles Kempton park is a big event, the AMC pistons are scarce I am afraid.

Unfortunately no where near Kempton, even Newark is a stretch, but Rufforth, Wetherby and Scorton are just about on the doorstep...and I've spotted nothing so far. Are the rings as scarce as the pistons? I seem to be collecting barrels and heads but nothing to go in them! Even picked up a few 25T bits along the way by accident.

Villiers Services recently had a batch of Villiers 4T pistons made in all oversizes (with rings and gudgeon pins); these pistons were previously unobtainable. Perhaps the FBOC should talk to Steve Gollings of VS to discuss the manufacture of AMC pistons - I suspect the required minimum batch order would be very large.

That's very interesting about the 4T pistons Sandy,what every the the T20 piston min requirement would be if it every happened, I am sure there would be buyers.I wonder how many AMC T20 engine's were made.perhape's some one as a stock of them in there shed at the bottom of the garden and doe's not know how valuable they are.

hi to all interested in AMC pistons there is no shortage of any size AMC pistons 15t 17t 20t 25t in standard sizes and over sizes. Bantam John has all these plus much more AMC engine parts and cycle parts just ask but know exactly what you want before you enquire. Ring Sheffield British Motorcycles on 01246290021. Stuart Elkes.

If you have a failure to find AMC 250cc pistons, the Classic Motorcycle Club in Johannesburg, South Africa have a number of NoS pistons that they obtained with a load of spares from Zimbabwe. Contact the club chairman at chairman@classicmotorcycleclub.co.za and he should be able to inform you of quantity & what sizes are available. BobH